The desolventizer toaster (DT) is an equipment which has been utilized in a number of contexts over the years. It is particularly applicable for processing agricultural commodities. There are a number of advantages which can be obtained by processing granular material or meal in a manner known in the prior art.
Nevertheless, there are shortcomings inherent in the manner in which processing is conducted in the prior art. A DT known in the art employs a plurality of generally parallel, vertically spaced trays mounted within a housing. The material to be processed is contacted with water or steam, or a mixture of the two, which is introduced into the equipment housing at the bottom of the DT. Moisture is thereby afforded to form an azeotrope in the upper trays and to avoid excessive drying of the product. Meal passes downwardly through each tray by transiting through an open hole through which passage is controlled by a gate mechanism. During the processing, solvent heavy vapors are removed from the material being processed. Because various solvents, including hexane, have a density significantly in excess of the density of steam, there is a tendency for the almost pure solvent to boil off at the top of the trays in the upper section and cascade into the lower trays. Such a consequence can lead to contamination of the nearly pure steam environment in the lower section of the DT. The desolventizing which has progressed to a desired point can, as a result, be negated.
It is to these shortcomings and deficiencies of the prior art that the present invention is directed. It is an improved structure which serves to solve problems existent with equipments known in the prior art.